Rechargeable batteries have been in use for almost as long as motor vehicles carrying such batteries have existed. For almost one hundred years, the discharge of charged automobile batteries has been monitored and responded to through the simplest of battery charge/discharge dashboard gauges. However, over the past generation, the distribution loads imposed upon automotive batteries during the discharge periods, when the battery is not being charged by automobile, have increased. Furthermore, the distribution of the battery power is becoming increasingly complex and hard to monitor. This leads to potential failures of battery functions that are essential to the automobile, such as power for the automobile starter.
In present day conventional motor vehicles, powerful audio systems consume battery power, as do television devices and heat/cool climate control devices. Hybrid automobiles that alternate battery power and combustion power, as needed, present an even greater need for controlling battery power distribution during discharge periods. Ultimately, the power distribution is critical in fully electrical automobiles wherein the automobile is running on the discharging of the charged battery.